/* Copyright (C) 2007 Google Inc.
 Copyright (c) 2008 MySQL AB, 2008-2009 Sun Microsystems, Inc.
 Use is subject to license terms.

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; version 2 of the License.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA */

#include "semisync_master.h"
#include "sql_class.h"                          // THD

ReplSemiSyncMaster repl_semisync;

C_MODE_START

int repl_semi_report_binlog_before_recovery(Binlog_storage_param *param, const char * server_uuid,
                                            PSI_file_key * key_file_binlog_index, const char * log_bin_index) {
    return 0;
}

int repl_semi_report_binlog_update(Binlog_storage_param *param, const char *dir_path, const char *prev_log_file,
                                   my_off_t prev_log_pos, const char *log_file, my_off_t log_pos) {
    int error = 0;

    if (repl_semisync.getMasterEnabled()) {
        /*
         Let us store the binlog file name and the position, so that
         we know how long to wait for the binlog to the replicated to
         the slave in synchronous replication.
         */
        error = repl_semisync.writeTranxInBinlog(log_file, log_pos);
    }

    return error;
}

int repl_semi_request_commit(Trans_param *param) {
    return 0;
}

int repl_semi_report_commit(Trans_param *param) {

    bool is_real_trans = param->flags & TRANS_IS_REAL_TRANS;

    if (is_real_trans && param->log_pos) {
        const char *binlog_name = param->log_file;
        return repl_semisync.commitTrx(binlog_name, param->log_pos);
    }
    return 0;
}

int repl_semi_report_rollback(Trans_param *param) {
    return repl_semi_report_commit(param);
}

int repl_semi_binlog_dump_start(Binlog_transmit_param *param, const char *log_file, my_off_t log_pos) {
    bool semi_sync_slave = repl_semisync.is_semi_sync_slave();

    if (semi_sync_slave) {
        /* One more semi-sync slave */
        repl_semisync.add_slave();
        /* Tell server it will observe the transmission.*/
        param->set_observe_flag();

        /*
         Let's assume this semi-sync slave has already received all
         binlog events before the filename and position it requests.
         */
        repl_semisync.reportReplyBinlog(param->server_id, log_file, log_pos);
    } else
        param->set_dont_observe_flag();

    sql_print_information("Start %s binlog_dump to slave (server_id: %d), pos(%s, %lu)",
                          semi_sync_slave ? "semi-sync" : "asynchronous", param->server_id, log_file,
                          (unsigned long) log_pos);

    return 0;
}

int repl_semi_binlog_dump_end(Binlog_transmit_param *param) {
    bool semi_sync_slave = repl_semisync.is_semi_sync_slave();

    sql_print_information("Stop %s binlog_dump to slave (server_id: %d)",
                          semi_sync_slave ? "semi-sync" : "asynchronous", param->server_id);
    if (semi_sync_slave) {
        /* One less semi-sync slave */
        repl_semisync.remove_slave();
    }
    return 0;
}

int repl_semi_reserve_header(Binlog_transmit_param *param, unsigned char *header, unsigned long size,
                             unsigned long *len) {
    *len += repl_semisync.reserveSyncHeader(header, size);
    return 0;
}

int repl_semi_before_send_event(Binlog_transmit_param *param, unsigned char *packet, unsigned long len,
                                const char *log_file, my_off_t log_pos) {
    return repl_semisync.updateSyncHeader(packet, log_file, log_pos, param->server_id);
}

int repl_semi_after_send_event(Binlog_transmit_param *param, const char *event_buf, unsigned long len,
                               const char * skipped_log_file, my_off_t skipped_log_pos) {
    if (repl_semisync.is_semi_sync_slave()) {
        if (skipped_log_pos > 0)
            repl_semisync.skipSlaveReply(event_buf, param->server_id, skipped_log_file, skipped_log_pos);
        else {
            THD *thd = current_thd;
            /*
             Possible errors in reading slave reply are ignored deliberately
             because we do not want dump thread to quit on this. Error
             messages are already reported.
             */
            (void) repl_semisync.readSlaveReply(&thd->net, param->server_id, event_buf);
            thd->clear_error();
        }
    }
    return 0;
}

int repl_semi_reset_master(Binlog_transmit_param *param) {
    if (repl_semisync.resetMaster())
        return 1;
    return 0;
}

C_MODE_END

/*
 semisync system variables
 */
static void fix_rpl_semi_sync_master_timeout(MYSQL_THD thd, SYS_VAR *var, void *ptr, const void *val);

static void fix_rpl_semi_sync_master_trace_level(MYSQL_THD thd, SYS_VAR *var, void *ptr, const void *val);

static void fix_rpl_semi_sync_master_enabled(MYSQL_THD thd, SYS_VAR *var, void *ptr, const void *val);

static MYSQL_SYSVAR_BOOL(enabled, rpl_semi_sync_master_enabled,
        PLUGIN_VAR_OPCMDARG,
        "Enable semi-synchronous replication master (disabled by default). ",
        NULL, 			// check
        &fix_rpl_semi_sync_master_enabled,// update
        0);

static MYSQL_SYSVAR_ULONG(timeout, rpl_semi_sync_master_timeout,
        PLUGIN_VAR_OPCMDARG,
        "The timeout value (in ms) for semi-synchronous replication in the master",
        NULL,// check
        fix_rpl_semi_sync_master_timeout,// update
        10000, 0, ~0UL, 1);

static MYSQL_SYSVAR_BOOL(wait_no_slave, rpl_semi_sync_master_wait_no_slave,
        PLUGIN_VAR_OPCMDARG,
        "Wait until timeout when no semi-synchronous replication slave available (enabled by default). ",
        NULL,// check
        NULL,// update
        1);

static MYSQL_SYSVAR_ULONG(trace_level, rpl_semi_sync_master_trace_level,
        PLUGIN_VAR_OPCMDARG,
        "The tracing level for semi-sync replication.",
        NULL,// check
        &fix_rpl_semi_sync_master_trace_level,// update
        32, 0, ~0UL, 1);

static SYS_VAR* semi_sync_master_system_vars[] = { MYSQL_SYSVAR(enabled), MYSQL_SYSVAR(timeout), MYSQL_SYSVAR(
        wait_no_slave), MYSQL_SYSVAR(trace_level), NULL, };

static void fix_rpl_semi_sync_master_timeout(MYSQL_THD thd, SYS_VAR *var, void *ptr, const void *val) {
    *(unsigned long *) ptr = *(unsigned long *) val;
    repl_semisync.setWaitTimeout(rpl_semi_sync_master_timeout);
    return;
}

static void fix_rpl_semi_sync_master_trace_level(MYSQL_THD thd, SYS_VAR *var, void *ptr, const void *val) {
    *(unsigned long *) ptr = *(unsigned long *) val;
    repl_semisync.setTraceLevel(rpl_semi_sync_master_trace_level);
    return;
}

static void fix_rpl_semi_sync_master_enabled(MYSQL_THD thd, SYS_VAR *var, void *ptr, const void *val) {
    *(char *) ptr = *(char *) val;
    if (rpl_semi_sync_master_enabled) {
        if (repl_semisync.enableMaster() != 0)
            rpl_semi_sync_master_enabled = false;
    } else {
        if (repl_semisync.disableMaster() != 0)
            rpl_semi_sync_master_enabled = true;
    }

    return;
}

Trans_observer trans_observer = { sizeof(Trans_observer),		// len

        repl_semi_report_commit,	// after_commit
        repl_semi_report_rollback,	// after_rollback
        };

Binlog_storage_observer storage_observer = { sizeof(Binlog_storage_observer),  // len

        repl_semi_report_binlog_update,  // report_update
        repl_semi_report_binlog_before_recovery,  // before_recovery
        };

Binlog_transmit_observer transmit_observer = { sizeof(Binlog_transmit_observer),  // len

        repl_semi_binlog_dump_start,	// start
        repl_semi_binlog_dump_end,	// stop
        repl_semi_reserve_header,  // reserve_header
        repl_semi_before_send_event,	// before_send_event
        repl_semi_after_send_event,	// after_send_event
        repl_semi_reset_master,	// reset
        };

#define SHOW_FNAME(name)			\
  rpl_semi_sync_master_show_##name

#define DEF_SHOW_FUNC(name, show_type)					\
  static  int SHOW_FNAME(name)(MYSQL_THD thd, SHOW_VAR *var, char *buff) \
  {									\
    repl_semisync.setExportStats();					\
    var->type= show_type;						\
    var->value= (char *)&rpl_semi_sync_master_##name;				\
    return 0;								\
  }

DEF_SHOW_FUNC(status, SHOW_BOOL)
DEF_SHOW_FUNC(clients, SHOW_LONG)
DEF_SHOW_FUNC(wait_sessions, SHOW_LONG)
DEF_SHOW_FUNC(trx_wait_time, SHOW_LONGLONG)
DEF_SHOW_FUNC(trx_wait_num, SHOW_LONGLONG)
DEF_SHOW_FUNC(net_wait_time, SHOW_LONGLONG)
DEF_SHOW_FUNC(net_wait_num, SHOW_LONGLONG)
DEF_SHOW_FUNC(avg_net_wait_time, SHOW_LONG)
DEF_SHOW_FUNC(avg_trx_wait_time, SHOW_LONG)

/* plugin status variables */
static SHOW_VAR semi_sync_master_status_vars[] = { { "Rpl_semi_sync_master_status", (char*) &SHOW_FNAME(status),
        SHOW_FUNC }, { "Rpl_semi_sync_master_clients", (char*) &SHOW_FNAME(clients), SHOW_FUNC }, {
        "Rpl_semi_sync_master_yes_tx", (char*) &rpl_semi_sync_master_yes_transactions, SHOW_LONG }, {
        "Rpl_semi_sync_master_no_tx", (char*) &rpl_semi_sync_master_no_transactions, SHOW_LONG }, {
        "Rpl_semi_sync_master_wait_sessions", (char*) &SHOW_FNAME(wait_sessions), SHOW_FUNC }, {
        "Rpl_semi_sync_master_no_times", (char*) &rpl_semi_sync_master_off_times, SHOW_LONG }, {
        "Rpl_semi_sync_master_timefunc_failures", (char*) &rpl_semi_sync_master_timefunc_fails, SHOW_LONG }, {
        "Rpl_semi_sync_master_wait_pos_backtraverse", (char*) &rpl_semi_sync_master_wait_pos_backtraverse, SHOW_LONG },
        { "Rpl_semi_sync_master_tx_wait_time", (char*) &SHOW_FNAME(trx_wait_time), SHOW_FUNC }, {
                "Rpl_semi_sync_master_tx_waits", (char*) &SHOW_FNAME(trx_wait_num), SHOW_FUNC }, {
                "Rpl_semi_sync_master_tx_avg_wait_time", (char*) &SHOW_FNAME(avg_trx_wait_time), SHOW_FUNC }, {
                "Rpl_semi_sync_master_net_wait_time", (char*) &SHOW_FNAME(net_wait_time), SHOW_FUNC }, {
                "Rpl_semi_sync_master_net_waits", (char*) &SHOW_FNAME(net_wait_num), SHOW_FUNC }, {
                "Rpl_semi_sync_master_net_avg_wait_time", (char*) &SHOW_FNAME(avg_net_wait_time), SHOW_FUNC }, { NULL,
                NULL, SHOW_LONG }, };

#ifdef HAVE_PSI_INTERFACE
PSI_mutex_key key_ss_mutex_LOCK_binlog_;

static PSI_mutex_info all_semisync_mutexes[]=
{
    {   &key_ss_mutex_LOCK_binlog_, "LOCK_binlog_", 0}
};

PSI_cond_key key_ss_cond_COND_binlog_send_;

static PSI_cond_info all_semisync_conds[]=
{
    {   &key_ss_cond_COND_binlog_send_, "COND_binlog_send_", 0}
};
#endif /* HAVE_PSI_INTERFACE */

PSI_stage_info stage_waiting_for_semi_sync_ack_from_slave = { 0, "Waiting for semi-sync ACK from slave", 0 };

#ifdef HAVE_PSI_INTERFACE
PSI_stage_info *all_semisync_stages[]=
{
    & stage_waiting_for_semi_sync_ack_from_slave
};

static void init_semisync_psi_keys(void)
{
    const char* category= "semisync";
    int count;

    count= array_elements(all_semisync_mutexes);
    mysql_mutex_register(category, all_semisync_mutexes, count);

    count= array_elements(all_semisync_conds);
    mysql_cond_register(category, all_semisync_conds, count);

    count= array_elements(all_semisync_stages);
    mysql_stage_register(category, all_semisync_stages, count);
}
#endif /* HAVE_PSI_INTERFACE */

static int semi_sync_master_plugin_init(void *p) {
#ifdef HAVE_PSI_INTERFACE
    init_semisync_psi_keys();
#endif

    if (repl_semisync.initObject())
        return 1;
    if (register_trans_observer(&trans_observer, p))
        return 1;
    if (register_binlog_storage_observer(&storage_observer, p))
        return 1;
    if (register_binlog_transmit_observer(&transmit_observer, p))
        return 1;
    return 0;
}

static int semi_sync_master_plugin_deinit(void *p) {
    if (unregister_trans_observer(&trans_observer, p)) {
        sql_print_error("unregister_trans_observer failed");
        return 1;
    }
    if (unregister_binlog_storage_observer(&storage_observer, p)) {
        sql_print_error("unregister_binlog_storage_observer failed");
        return 1;
    }
    if (unregister_binlog_transmit_observer(&transmit_observer, p)) {
        sql_print_error("unregister_binlog_transmit_observer failed");
        return 1;
    }
    sql_print_information("unregister_replicator OK");
    return 0;
}

struct Mysql_replication semi_sync_master_plugin = { MYSQL_REPLICATION_INTERFACE_VERSION };

/*
 Plugin library descriptor
 */
mysql_declare_plugin (semi_sync_master) { MYSQL_REPLICATION_PLUGIN, &semi_sync_master_plugin, "rpl_semi_sync_master",
        "He Zhenxing", "Semi-synchronous replication master", PLUGIN_LICENSE_GPL, semi_sync_master_plugin_init, /* Plugin Init */
        semi_sync_master_plugin_deinit, /* Plugin Deinit */
        0x0100 /* 1.0 */, semi_sync_master_status_vars, /* status variables */
        semi_sync_master_system_vars, /* system variables */
        NULL, /* config options */
        0, /* flags */
}
mysql_declare_plugin_end;
